Nasogastric tubes are available in a variety of sizes and materials, the selection for any given patient depending on factors such as the size or age of the patient, the expected duration of the intubation, and the precise purpose for such intubation. In general, nasogastric tubes are commonly available in sizes ranging between 6 to 18 French (about 0.080 to 0.240 inches), and the materials from which they are formed may be relatively soft or of low durometer such as, for example, silicone rubber, or considerably stiffer or of higher durometer, such as polyvinyl chloride. The stiffer materials are needed when such a tube is to be used for aspirating purposes, since the material must be capable of resisting collapse when suction is applied, whereas the softer materials are frequently used for feeding purposes, especially where relatively long-term use is anticipated.
While various types of nasogastric tube holders have been disclosed in the prior art, such devices are all believed to have significant shortcomings. Quite typically, such a device includes an adhesive patch or a strap for attachment to the patient, coupled with holding means for securing the nasogastric tube to the patch or strap. The holding means often takes the form of adhesive tape (U.S. Pat. Nos. 4,142,527, 3,046,989, 3,146,778, 3,977,407) but such tape, although capable of accommodating tubes of different size, is not readily detachable from the tubes when removal or adjustment is required. Mechanical holding means (U.S. Pat. Nos. 4,831,487, 4,120,304) generally involve slotted U-shaped members formed of relatively rigid plastic and, while slidable adjustment or detachment may be readily accomplished, such holders cannot connect to tubes of different size nor are they adjustable to insure secure attachment to tubes of the same size but different degrees of softness Also, with mechanical holders carried by an elongated strap (e.g., 4,120,304) as well as with devices utilizing tape or sutures as the holding means (3,146,778), a pistoning action of the tube may occur and result in considerable discomfort and possible injury to the patient. Clamping devices capable of detachably receiving nasogastric tubes of different size are known (4,282,871, 4,480,639), but such clamps are of the spring-action type and, therefore, any force sufficient to overcome the bias of the springs may result in release of the tubes and, again, possibly serious risks for the patients.
Accordingly, one aspect of this invention lies in providing a device having a pair of clamping jaws that are readily adjustable for holding nasogastric tubes of different size and durometer, may be securely latched together and maintained in such latched condition by positive action rather than spring action, and are nevertheless separable when disconnection from or adjustment of a nasogastric tube is required. The clamping jaws are pivotally mounted immediately adjacent the edge of a flexible pad that is adhesively secured over a wearer's nose when the device is in use, and the close proximity of the jaws to the end of the patient's nose, and the relative stiffness of that portion of the pad overlying the ridge of the nose, eliminates or greatly reduces the likelihood of pistoning action. Although the clamping jaws securely hold a nasogastric tube in place, effectively resisting forces tending to move the tube longitudinally, the clamp may be easily and quickly released by intentional lateral displacement of a flexible latching arm provided by one of the jaws.
Most advantageously, the pad takes the form of a thin layer of soft, porous sheet material such as the soft, non-occlusive tapes commonly used in the medical field. The underside of the sheet or tape is coated with a pressure-sensitive adhesive and, in a preferred embodiment, a layer of skin-barrier material may be secured to that portion of the underside of the tape that extends over the ridge of a wearer's nose. Secured to the upper surface of the tape by an adhesive patch that is preferably formed of the same material as the tape is a mounting plate that gives the pad a desired contour, adds stiffness to the pad along the ridge of the wearer's nose, and provides support for the pivot pin on which the jaws are mounted. By providing the plate with a socket and the pivot pin with a barbed end portion, the clamping arms may be joined to the pad as the final step in the manufacture of the device.
Therefore, the device essentially comprises a flexible, non-occlusive, adhesive pad that is adapted for adhesive attachment to a patient's nose, a pivot pin secured to the pad adjacent one of its edges, and a pair of clamping jaws pivotally supported by the pin for movement between closed and open positions. The jaws are provided with adjustable latching means for selectively and releasably latching the jaws in any of a plurality of closed positions, with the result that nasogastric tubes of different outside diameters and different degrees of softness may be effectively clamped and retained by the jaws. The latching means takes the form of ratchet teeth provided by the jaws, one of the jaws having a series or rack of such teeth, and the other jaw having at least one ratchet tooth selectively engagable with the teeth of the first jaw. The two jaws have arcuate faces disposed in opposition when the jaws are closed, at least one of the arcuate faces including a narrow bearing rib and the other jaw having a bearing surface that directly opposes the rib when the jaws are closed. Because of such construction, closing of the jaws, even about a tube of relatively small size, does not result in a scissoring action nor does it tend to cause a twisting of the nasogastric tube out of parallel relation with the pivot axis of the jaws.